1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 // <functional>
10
11 // template<class R, class ...Args>
12 // function(R(*)(Args...)) -> function<R(Args...)>;
13
14 // UNSUPPORTED: c++03, c++11, c++14
15
16 #include <functional>
17 #include <type_traits>
18
19 #include "test_macros.h"
20
21 struct R { };
22 struct A1 { };
23 struct A2 { };
24 struct A3 { };
25
f0()26 R f0() { return {}; }
f1(A1)27 R f1(A1) { return {}; }
f2(A1,A2)28 R f2(A1, A2) { return {}; }
f3(A1,A2,A3)29 R f3(A1, A2, A3) { return {}; }
f4(A1={})30 R f4(A1 = {}) { return {}; }
31
main(int,char **)32 int main(int, char**) {
33 {
34 // implicit
35 std::function a = f0;
36 ASSERT_SAME_TYPE(decltype(a), std::function<R()>);
37
38 std::function b = &f0;
39 ASSERT_SAME_TYPE(decltype(b), std::function<R()>);
40
41 // explicit
42 std::function c{f0};
43 ASSERT_SAME_TYPE(decltype(c), std::function<R()>);
44
45 std::function d{&f0};
46 ASSERT_SAME_TYPE(decltype(d), std::function<R()>);
47 }
48 {
49 // implicit
50 std::function a = f1;
51 ASSERT_SAME_TYPE(decltype(a), std::function<R(A1)>);
52
53 std::function b = &f1;
54 ASSERT_SAME_TYPE(decltype(b), std::function<R(A1)>);
55
56 // explicit
57 std::function c{f1};
58 ASSERT_SAME_TYPE(decltype(c), std::function<R(A1)>);
59
60 std::function d{&f1};
61 ASSERT_SAME_TYPE(decltype(d), std::function<R(A1)>);
62 }
63 {
64 // implicit
65 std::function a = f2;
66 ASSERT_SAME_TYPE(decltype(a), std::function<R(A1, A2)>);
67
68 std::function b = &f2;
69 ASSERT_SAME_TYPE(decltype(b), std::function<R(A1, A2)>);
70
71 // explicit
72 std::function c{f2};
73 ASSERT_SAME_TYPE(decltype(c), std::function<R(A1, A2)>);
74
75 std::function d{&f2};
76 ASSERT_SAME_TYPE(decltype(d), std::function<R(A1, A2)>);
77 }
78 {
79 // implicit
80 std::function a = f3;
81 ASSERT_SAME_TYPE(decltype(a), std::function<R(A1, A2, A3)>);
82
83 std::function b = &f3;
84 ASSERT_SAME_TYPE(decltype(b), std::function<R(A1, A2, A3)>);
85
86 // explicit
87 std::function c{f3};
88 ASSERT_SAME_TYPE(decltype(c), std::function<R(A1, A2, A3)>);
89
90 std::function d{&f3};
91 ASSERT_SAME_TYPE(decltype(d), std::function<R(A1, A2, A3)>);
92 }
93 // Make sure defaulted arguments don't mess up the deduction
94 {
95 // implicit
96 std::function a = f4;
97 ASSERT_SAME_TYPE(decltype(a), std::function<R(A1)>);
98
99 std::function b = &f4;
100 ASSERT_SAME_TYPE(decltype(b), std::function<R(A1)>);
101
102 // explicit
103 std::function c{f4};
104 ASSERT_SAME_TYPE(decltype(c), std::function<R(A1)>);
105
106 std::function d{&f4};
107 ASSERT_SAME_TYPE(decltype(d), std::function<R(A1)>);
108 }
109
110 return 0;
111 }
112